4th Gen 4runner suspension refresh, calling all suspension guru's

BC Adventurist

New member
Hey everyone,

It's time for me to start looking a lot more seriously into refreshing the suspension in the 4Runner. She's got 330k km's on the clock with a mixed bag of suspension components.

Front end:
Bilstein 5100's w/ 2nd Gen Tacoma coils (~75k km on the shocks, unknown on the springs) on 3rd perch
SPC upper control arms, OEM lower control arms, sway bar endlinks and bushings (reasonably new, ~275k on the clock when installed)

Rear end:
ICON VS 2.0 with ICON 2" lift coils (40-50k km)
new sway bushings and extended endlinks
original linkages

This setup has treated us fairly well while I was broke in school but recently we've been less and less thrilled with the handling of the truck. She's got a fair bit of roll, particularly on tighter s-bend sections of road with broken pavement, which is common around us. The rear end seems to have some bounce to it as well which suggests that the shocks are nearly due for replacement or possibly just they are under valved for the current weight. The front end is fairly close to stock weight; we've got a group 31 battery, custom engine skid, and sliders so I'd estimate around 100-125lb heavier than stock on the front end. The rear end, however, is porky; sliders, oversize spare (running 265/70r18 tires), custom drawer system with tools, basic recovery gear, compressor, fridge, etc (maybe 250lb), an RTT, and a 65lb bike rack in the hitch. There is a scale in town so I could get my axle weight, but without knowing what it is stock/empty its of limited value so far.

I've wanted to go Bilstein 6112 in the front for years, pretty much since the system came out. I can't justify Icon/Fox/King/etc as we don't drive enough and the winters here would end up destroying them, negating the ability to rebuild. The sensible option may be to go OME but I've never ridden in a 4Runner running OME gear so I have no feel for the ride, and enough people find it too firm which could make highway drives not so fun (twisting two lanes with lots of bumps, dips and broken pavement here). The rear end is where I'm really struggling, particularly if I want to pair with 6112's in the front. I doubt the valving in the 5160's is adequate for the weight, I'm doubting the Icon VS2.0's as well if/once I go to a higher spring rate. How heavy can one go with the spring rate while maintaining a compliant ride on logging roads? Will progressive OME match with Digressive Bilstein? Probably not so well...

Should I be considering replacing all my rear links, what are the odds that's where the lousy handling is coming from?

I'm hoping there are others that have been through a similar dilemma and found good results. Lets hear it!
 
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Neosapian

Member
Typically you are going to have to choose between road comfort and load carrying capability. I believe that complete suspension and lift kits with matching front and rear shock & spring components are likely to perform better than a setup comprised of multi-branded or mis-matched spring and shock combinations.

Brands like Old Man Emu or Fox spend thousands of hours developing, testing, sourcing and manufacturing their suspension parts to perform as a set. What you run in the front of your truck will impact the performance of what you're running in the rear, and vice-versa. If a combination of shock & spring or front & rear suspension components has not been specifically designed to run with one another, I'd guess there's a decent chance of less-than-ideal performance. But you probably already know this.

Body roll and sway is going to happen on a vehicle, no matter what. Especially with a body-on-frame vehicle with a high center of gravity. I have a 2016 Volkswagen GTI with the adjustable suspension and every other factory option, and even that little guy has body roll. In the 4runner I drive to weather and road conditions and remind myself im in a truck, not a track-ready Mazda Miata.

I am very picky about ride quality in my vehicles, so choosing a suspension has never been an easy decision for me. If you'd like I'll share my experience with an Old Man Emu setup on my 4th Gen V8 4x4 on 285/70r17 Cooper ST Maxx tires. Its a mid-length read though, so I don't want to bother you with details quite yet if you aren't interested in OME's stuff.
 

chmura

Adventurer
Icon 2.0 VS in the rear are crap. I had two sets of these shocks in the rear of my 2009 4runner and everyone of them leaked. Not just a fluke, they are garbage. The rear of the 4runner takes the most abuse shock wise so it is smart to get a very good shock back there, 2.5 Icon or King.
 

BC Adventurist

New member
Hey everyone,

I appreciate the feedback so far. Neosapien, I'm not afraid to do some reading so shoot me the link, I've done tons of searches so far but nothing that's quite lined up with what I'm trying to accomplish. I'm absolutely aware that body roll is par for the course but I had better driving feedback from my 3rd gen with the Sonoran Steel kit (really flexy rear). I'm fairly certain the handling and ride quality has decreased from when everything was fresh, which isn't hugely surprising but I don't want to replace with the same. To give you an idea of what it's driving like, and perhaps you can confirm your OME equipped runner was the same, when I turn into a corner there is a very obvious amount of time before the truck matches what the tires are doing (100-150ms easily). This is enough of a delay that my partner had a bad habit of turning in, felt the truck wasn't turning, would turn in more then have to correct as the truck turned too far into the corner. Others who drove the truck do the same thing.

I ended up weighing it on the way out last weekend for some camping, so full of fuel, 2 people, packed light (only an overnighter and I'm not a big packer) and no bike rack. 2520kg (5540lb) overall, 1320kg (2900lb) on the rear axle. Handling was a bit better, and the bounce was definitely reduced without the bike rack.

chmura, the Icon's were definitely an improvement vs the bilstein's that were back there before (blew both of those and they couldn't handle weight at all). It's definitely possible the Icon's are tired but I see no evidence of weep from the seals. Were your rear shocks built by Icon, or the previous version built by a 3rd party? Sadly I have Canadian pesos to spend so I don't think large bore Icon or King are on the menu for me, especially if I want to match the front. I do agree they rear shocks will take some abuse, lots of weight and lots of travel (pro's and con's here for shock cycling) but I'm not sure they are beaten up more than the front; the leverage ratio caused by the control arms is not helpful in the least.

I've been through that T4R thread before, don't find a ton of meat there that's useful (really could have done with vehicle weights to go with shock selection) which is why I'm here, Expo people seem to be more aware of weight and how that affects suspension selection.

Cheers,
 

Neosapian

Member
Here We Go...

I'll preface my opinion by pointing out that my 4runner is a daily driver, 149k miles. I don't have a lot of 4x4 experience, but the experience I have with OME on my 4runner is thorough. So far I've been aired down and off road in the mountains of Northwest Washington, British Columbia, and southern Oregon, Hells Revenge and associated trails in Moab, Canyonland’s White Rim Trail, and throughout Death Valley’s trail system. I prefer to keep a decent pace both on and off road and I don’t baby my rig by any means. I hope this outline serves as a useful data point for you.

Front Setup

OME Nitrocharger 90000 Shocks with "Medium Load" 2885 springs with driver side "trim packer" and 1//4” polyurethane top spacers. 90000 shocks are valved 15% stiffer than their 90021 counterparts. The 2885 springs are recommended for 70-180lbs of additional weight on the front end. I chose this combination in anticipation of installing my Warn VR10S (60lbs) winch into a ~70lbs Pelfrey Aluminum front bumper. Due to time constraints prior to a 3500 mile camping trip last October, I didn't end up ordering a bumper or mounting the winch so the only additional weight up front is a single Group 31 Odyssey, 75lbs. I installed a new KYB strut mount kit, Part# SM560. Its one of the least expensive means of eliminating excess slop and vibration from the front suspension and steering system.

I'm running stock upper control arms at the moment. For practical purposes my front alignment is "fine", and I reckon I could run my 285/70r17 ST Maxx's for about 6000 miles before mis-alignment begins to negatively effect tire wear. The decision to postpone adjustable uppers was dictated by my budget, as I wanted other more immediately necessary items. If you have the cash I recommend doing your uppers at the same time as your lift.

I trimmed my body mounts. My sway bar is removed. The additional up-travel is nice, but causes rubbing issues that Im not motivated to rectify. I'll be towing a travel trailer soon, so the sway bar has to go back on anyway.


Rear Setup

OME Nitrocharger 90005 shocks with 2896 "Heavy Load" springs. 90005 shocks are valved 15% stiffer than their 60004 counterparts. 2896 springs are recommended for use with a minimum of 330lbs of additional full-time payload, up to the toyota’s gross vehicle weight rating. They are 70% higher spring rate than stock, compared to the medium load 2895’s, which are 40% stiffer than stock. I chose the 2896 setup because my plywood drawers and fridge weigh 250lbs empty, plus 110lbs spare tire, 100lbs of water, 75lbs of camping gear etc. etc. I do not have an aftermarket rear bumper or tire carrier.


The Ride

The front suspension plays really well with just the weight of the V8 and a Group 31 battery. Comfort over irregularities, expansion joints and pot holes on highways is a non-issue, and its as comfortable as you could expect a truck with 33” LT rated all terrain tires to be. More specifically, zero harshness or vibration transmitted through the steering wheel or seat. Compression and rebound is quick. Zero bounce. 75mph down twisty mountain highways is planted, safe, confident... even without a front sway bar or XREAS. As long as tire pressures are above 32, I have excellent turn-in response and reasonably detailed feedback through the steering wheel mid-turn on the highways. OME gear manages the weight of the vehicle in a predictable and balance manner - corrections can be made mid-turn and emergency maneuvers around road hazards or Prius drivers is direct and manageable.

The rear 2896 springs - If the 4runner isn't loaded for a trip - on pavement with just the drawers and a full tank of gas; Very rough, very harsh, slightly annoying for me. My girlfriend doesn’t seem to mind it. On washboard forest service roads at moderate speeds without a fully loaded cargo area, the vibration and harshness transmitted through the rear of the vehicle is sufficient to literally rattle the rear tail gate latch open. I've often had to pull over and physically re-close and latch the tail gate en-route. It is important to note that there is NO bouncing or weirdness at all. There is a positive over-steer tendency on gravel, dirt and packed snow that will remind you to slow down or encourage you to add throttle and powerslide, depending on your mood. I always test my vehicles beyond their handling threshold so that I know what to expect, “in the event of”.

The "heavy” ’96 rears really come into their own when the truck has about 350+ lbs over the rear axle with 18-22psi in the tires. With 750lbs of people, fuel, water and gear, the ride comfort is firm but excellent. No excessive vibration or discomfort on or off road. Loaded and aired up on the highway, your rear passengers may not be happy with the Heavies but up front my girlfriend and I don’t have any complaints.

That said, the stiffer valved 60005 rear shock was absolutely the correct choice for me because I want the additional heat resistance and dampening under load for long stretches of washboard. I will be switching to the Medium 2895 rear springs however, which will soften the ride by 30% and offer a firm but not harsh ride quality while unloaded, and still handle the load carrying duties necessary to support my “overland loadout” plus the inevitable 550-600lbs tongue weight of a travel trailer. ARB Australia recommends rear air bags for headlight leveling purposes if my loadout reaches into the gross axle weight range.

Carrying capacity and excellent durability off roadis where OME pays for itself. Many people cross the Simpson Desert or the Canning Stock Routes in Australia with 6000+ lbs rigs on base model OME suspension. They’re designed for terrain harsher than anything we have access to in North America and the shocks are affordable enough to abuse and replace every 50k miles if you need to. Cheaper than rebuilding a remote res setup, actually. Rocky uneven terrain, dropping down rock steps, absorbing mud puddles, providing steering feedback on soft gravel when your rig is loaded down with people and gear...This is what OME has designed and tested their suspension for.

Monroe/ARB can price OME in the entry level range because they manufacture and distribute in internationally in high volume. They also use a very basic exterior finish treatment. The paint will chip and they won’t look pretty after 10k miles. My 4runner is a tool, not a jewel. I don’t need flashy looking suspension. It’s hidden behind my gashed up trail damaged wheels anyway.


Additional Thoughts

Prior to purchasing my suspension, I spoke at length with a rep at ARB/Old Man Emu Australia, an international call that cost me about 50 bucks. Well worth the education. I then consulted with ARB of Seattle for more clarification in addition to forum research. One thing I gathered is that opting for an excessive front spring rate can interact poorly with the rear weight bias common with heavily laden overland rigs. As weight is leveraged over or behind the rear axle, a high front spring rate will lift and exaggerate the distribution of weight rearward, reducing weight over the front wheels. This negatively impacts steering response and braking, and it causes the reverse rake that Tacoma guy's call "Bro Lean"... Err on the side of softer front spring rates for comfort and handling.

If I had the slightly lighter V6 up front, I’d opt for the slightly softer 90021 Nitrocharger Sport front shocks, and medium 2885 springs with 1/4” top spacer for a full 3” of lift to clear tires and enough spring rate to mitigate body roll and support future bumper, winch & batteries. If I didn’t plan on running such a heavy rear payload I’d opt for the softer 60004 rear rear shocks and medium 2895 springs. In my opinion those spring and dampening rates are close to how the truck should have come from the factory - especially considering how generous the payload and hitch weight ratings are on these trucks - higher even than a dual cab Tacoma in some cases…

Get set up with the correct OME shocks, 4 new sway bar end links and shock mounting hardware, check tire pressure, check your steering system and wheel bearings, and I reckon you'll be squared away.
 
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BC Adventurist

New member
Hey Neosapien,

Thanks for that detailed reply. You've given me a lot of good feedback and I can mostly relate to your setup, which is great. Have you ever gone over the scales with the truck empty/loaded? It sounds like I need to seriously think about 884/90021 combo in the front, and 895/60005 combo in the rear. Most of my front end is in pretty good shape, I have SPC UCA's, fresh LCA's, newer inner and outer tie rods, and new sway endlinks front and rear; its all the rear links that are still original. I did a pretty big overhaul in preparation for a 9k mile trip to the far north last summer. I'm definitely running plenty of tire pressure, ~38psi in the front, 40psi in the rear on LT-E Cooper AT3's.

I'm curious as to how different the 895's (40% stiffer) will be vs the Icon's I've got now (~20% stiffer) as I've read a few people who didn't notice much of a change between them, though you gotta think 20% change is noticeable.
 

Neosapian

Member
I'd assume that 20% difference in spring rate would make a noticeable difference, unless the Icon's are progressive, and only stiffen up under compression? I don't know. It sounds like the maintenance on your rig and your priorities are pretty much dialed. I can't imagine you'd be disappointed with 884's and 895's, or a similarly tuned setup from another brand.

Weighing my 4runner is something that I need to do. I'll swing by a CAT scale later this week and share the numbers. As for rear suspension linkages, I couldn't comment on how these might effect turn-in response or the like.

For what it's worth, I flew out of Washington State to purchase my 4runner in Chicago. 119k miles on it, 100% stock everything. There are some common corrosion issues caused by many years on salted winter roads - so the rear linkages are old and don't look very nice. Im at 239km now...No noticeable slop or noise from these original parts, and no handling related complaints to date. Yours probably had a better life than mine. I doubt your rear links are an issue.
 

BC Adventurist

New member
I've started to look into the Dobinson setups more seriously, looks like a good alternative to OME; I like the flexibility for spring options. Thanks matoolie for making me look into them a bit more
 

Tex68w

Beach Bum
OME, Toytec, or Dobinson for simple kits with good to very good performance and little to no maintenance or spend double for great to fantastic performance and get Icon, BP-51's or King's but be prepared to do rebuilds and mandatory scheduled maintenance. It really just boils down to how much you want to spend and/or how much time you want to mess with turning wrenches on your suspenders. I myself still haven't decided which way to go on our 5th Gen.
 

Neosapian

Member
I originally planned to go the Toytec route but through my own research I’ve gathered that their kits are more oriented toward lighter loadouts and/or lighter off-road duty. This makes sense to me considering their comparatively low spring rates and overwhelmingly positive remarks on daily ride comfort. I could be wrong about that.

I didn’t see a whole lot of North American reviews or coverage on Dobinsons when i was shopping around, though from what i can tell they’re super popular at least amongst Nissan GU and 79 Series guys in Australia. I haven’t dug deep enough yet to find out where or by whom their shocks are being manufactured.

As for the high end remote res suspension kits...A basic $1000 static lift kit will get a 4runner out to the same exact off road locations at reasonable speeds, without drama. If Im up in the Northern Territory BC or Alaska and i experience a rear shock failure, “simple” and “basic” is exactly what i want. Pack an inexpensive spare, DIY road-side swap in a matter of 2 hours, and never have to wait 1 - 2 weeks for replacement parts to arrive.

The “Second kind of cool” or bling factor of BP51’s is real. But for me there are so many other areas of a North American expo truck build that the extra cash could go.
 
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arctic04trd

Member
For the folks that are recommending OME and not Icons or Foxs......what exactly is your experience with suspension? Have you run anything other than twin tube mass produced shocks? I am never going back to OME after trying Icons on the Tacoma for the first time. I had OME on my first Tacoma and never thought I could justify twice as much money. I will be purchasing Icons or something similar for the 4runner.

If you guys have ridden in a truck on Icons or any monotube coilover/shock combo, then Im glad your butt doesnt require my lavish needs. And on the point of reliability in the middle of nowhere.......you can not expect to carry everything that will break with you. You may carry a shock, and have a diff explode or a ball joint fail. Your truck cant carry a whole set of spare parts for every eventuality. Just my two cents.
 

Neosapian

Member
I don’t expect my body on frame truck w/ LT rated tires to ride sophisticated, soft or particularly smooth. I have another car that fills that role. My 4runner is utilitarian. Its set up to run loaded up to GVWR. It happens to suffice while unloaded as a Daily.

Those who “Wheel” their built trucks break things... Even shocks & associated parts. Its just part of the hobby. Plenty of room for spare parts.

Those who have experienced a breakage or failure off road, during a multi-week long trip 2 or 3 states away from home for example might find it easier to appreciate the virtues of simplicity and serviceability even at the cost of comfort or bragging rights...Many do not turn their own wrenches or exercise their trucks so this might be a moot point.

If One could verify that Icon has their own full-stack manufacturing facility where they machine their own shock components and forge their own springs - i could better appreciate the price difference. The reality is that they almost certainly source from major OEM factories like the rest of the Industry, but do not experience the ultra high sales volume of the Monroe-built ARB/OME products. Therefore Icon’s higher price is partly a function of economy of scale and partly a function of their premium branding strategy. None of these factors contribute in any way to real world performance.

High load bareing static suspension is stiff. Comfortable suspension is soft and is less suitable for heavy loads. Pick your path. There are exceptions when you get into airbags or electro-hydraulic adjustability like on my GTi. Mechanically, there isn’t any secret sauce in Icon’s kit, is what im getting at.

My brother has a nice remote res Fox setup on his ‘08 Tacoma. It costs 4 times an OME kit. I don’t think it’s even 40% better as a daily driver (when ride comfort is paramount), let alone 400%. Then again I don’t race at freeway speeds down off road desert trails so the high end Icon and Fox capabilities are wasted on me. I suspect this is the case for the vast majority of us, though few will admit it.

Cheers to those running nicer Icon gear. If it serves your mission, I’m stoked! The performance envelope and Cool Factor is undeniable. See ya’ll on Instagram...err I meant, see yall on the Trail.

😂🤑🍺
 
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